Doped metal compounds, having a formula XYZ, wherein X and Y are one or more metals and Z is selected from one or more Group 13-16 elements, such as carbon, nitrogen, boron, silicon, sulfur, selenium, and tellurium, such as aluminum-doped metal carbide, may be used for a variety of applications. For example, aluminum-doped titanium carbide and similar materials may be used for gate electrodes in metal oxide field effect transistors (MOSFETs) or insulated gated field effect transistors (IGFETs), such as complementary metal oxide semiconductor (CMOS) devices, as a barrier layer or fill material for semiconductor or similar electronic devices, or as coatings in other applications.
When used as a layer of an electronic device or as a coating, the doped metal films are typically deposited using gas-phase deposition techniques, such as sputtering, chemical vapor deposition, or atomic layer deposition. As the number of deposition runs in a reactor increases, residue of the doped metal films may form in the reactor. As the residue of material increases within the reactor, the quality of the film deposited in the reactor may degrade—e.g., particles may form in the deposited film. To prevent or mitigate this degradation in film quality, the reactor may be periodically cleaned to remove the residue.
A typical clean process for a gas-phase reactor includes providing a gas-phase reactant that reacts with the residue material to be removed to form a more volatile compound. Unfortunately, gases, such as fluorine or other halide or halogen based etch chemistries that may be used to remove metal compounds may react to with constituents of the residue to form relatively nonvolatile compounds. For example, when fluorine is used to etch or remove aluminum doped metal carbide residue, the fluorine reacts with the aluminum to form aluminum fluoride, which is relatively nonvolatile. The aluminum fluoride material therefore acts as an etch barrier to removal of the residue.
Accordingly, improved methods and systems for etching or removing material having a formula XYZ, wherein X and Y are one or more metals and Z is selected from one or more Group 13-16 elements, such as carbon, nitrogen, boron, silicon, sulfur, selenium, and tellurium, are desired.